Secretion of virulence proteins from Campylobacter jejuni is dependent on a functional flagellar export apparatus
Secretion of virulence proteins from Campylobacter jejuni is dependent on a functional flagellar export apparatus
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DOI：
10.1128/jb.186.11.3296-3303.2004
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发表时间：
2004-06-01
影响因子：
3.2
通讯作者：
Mickelson, J
中科院分区：
文献类型：
--
作者：
Konkel, ME;Klena, JD;Mickelson, J
空肠弯曲杆菌是一种革兰氏阴性运动细菌，分泌一组称为弯曲杆菌入侵抗原（Cia蛋白）的蛋白质。本研究的目的是确定鞭毛装置是否作为Cia蛋白的输出装置。编码鞭毛基底（flgB和flgC）、钩（flgE2）和丝（flaA和flaB）基因的5个基因以及鞭毛蛋白输出所必需的基因（flhB和fliI）都发生了突变。虽然发现影响丝组装的突变是非运动的（Mot(-)），不分泌Cia蛋白（S-），但发现flaA （flaB(+)）丝突变是非运动的，但能够分泌Cia蛋白（Mot-， S'）。将flaA flaB双突变体与含有flaA或flaB基因的穿梭质粒互补，恢复了Cia蛋白的分泌，这表明Cia输出至少需要两种丝蛋白中的一种。用空肠梭菌突变体感染INT 407人肠细胞表明，上皮细胞的最大入侵需要具有分泌能力的运动细菌。总的来说，这些数据表明空肠C. Cia蛋白是从鞭毛出口器官分泌的。
Campylobacter jejuni, a gram-negative motile bacterium, secretes a set of proteins termed the Campylobacter invasion antigens (Cia proteins). The purpose of this study was to determine whether the flagellar apparatus serves as the export apparatus for the Cia proteins. Mutations were generated in five genes encoding three structural components of the flagella, the flagellar basal body (flgB and flgC), hook (flgE2), and filament (flaA and flaB) genes, as well as in genes whose products are essential for flagellar protein export (flhB and fliI). While mutations that affected filament assembly were found to be nonmotile (Mot(-)) and did not secrete Cia proteins (S-), a flaA (flaB(+)) filament mutant was found to be nonmotile but Cia protein secretion competent (Mot-, S'). Complementation of a flaA flaB double mutant with a shuttle plasmid harboring either the flaA or flaB gene restored Cia protein secretion, suggesting that Cia export requires at least one of the two filament proteins. Infection of INT 407 human intestinal cells with the C. jejuni mutants revealed that maximal invasion of the epithelial cells required motile bacteria that are secretion competent. Collectively, these data suggest that the C. jejuni Cia proteins are secreted from the flagellar export apparatus.